1. Field of the Invention
This invention relates to laying heads of the type employed in rolling mills to coil products such as hot rolled rods.
2. Description of the Prior Art
In the conventional laying head, as schematically depicted in FIG. 1 at 10, a hollow shaft 12 is journalled on bearings 14a,14b for rotation about an axis A. The shaft carries a three dimensionally curved laying pipe 16 having its entry end 16a arranged essentially concentric with the axis A, and its delivery end 16b located radially therefrom. Shaft 12 also carries a gear 18 which meshes with a gear 20 on a drive shaft 22, the latter being connected to a drive motor M. A hot rolled product, e.g., steel rod, is directed at mill delivery speeds along axis A into the shaft 12. The product then continues through the laying pipe 16 and exits therefrom in the form of a continuous series of rings 24. Typically, the rings will be received in an overlapping offset pattern on a conveyor 26 where they will be cooled at a controlled rate before finally being gathered into coils.
This type of laying head has operated satisfactorily in the past. However, future difficulties are envisioned as a result of ever increasing mill delivery speeds, particularly with respect to rod mills. For example, current modern day high speed rod mills are operating at mill delivery speeds of around 100 m/sec., thus requiring the laying head shafts to be driven at speeds of around 2,000 RPM. Such speeds are at the high end of the permissible operating range of the shaft bearings. Higher rod mill delivery speeds on the order of 150 m/sec. are now being planned but are in danger of not being implemented due to the inability of the conventional laying heads to accommodate further speed increases.
The objective of the present invention is to provide an improved laying head which has the capability of operating at much higher speeds, without overtaxing the capacity of the shaft bearings.